elkington



July 26,1955 .1. E. ELKINGTON AUTOMATIC D ISHWASHING DEVICE 3 Sheets-Sheet l Filed June 30, 1952 \r L l L l IN V EN TOR. ./A/vii fur/Na ro/v July 26, 1955 J. E. ELKINGTON AUTOMATIC DISHWASHING DEVICE I5 Sheets-Sheet 2 Filed June 30, 1952 INVENTOR. ./AMI.; i x//varo/v rropwiri July 26, 1955 J. E. ELklNGToN 2,713,855

AUTOMATIC DISHWASHING DEVICE Filed June 50, 1952 3 Sheets-Sheet 3 United States Patent O AUTOMATIC DISHWASHING DEVICE .lames E. Elkington, San Francisco, Calif. Application June 30, 1952, Serial No. 296,309 3 Claims. (Cl. 134-58) This invention relates to dishwashing machines.

A primary object of the present invention is to provide in a dishwashing machine of the type having a door closing a washing and rinsing compartment of the machine, a hydraulic actuator for opening said door; to provide such a machine in which the washing and rinsing operations cannot begin until the door is closed; and to provide a novel drain and lill system for draining soapy or like water from and supplying a new charge of water to the machine. I

Various other objects of the present invention will be apparent from the following description taken in connection with theaccompanying drawings wherein:

Fig. 1 is a side elevational View of a dishwashing machine embodying the concepts of the present invention, with parts broken away for convenience in illustration.

Fig. 2 is an enlarged fragmentary vertical sectional view of the hydraulic actuator and the associated parts.

Fig. 3 is an enlarged fragmentary vertical sectional view of part of the drain system.

Fig. 4 is a vertical sectional view taken along line 4 4 of Fig. 3.

Fig. 5 is a schematic wiring diagram of the control system of the machine.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, there is disclosed a dishwashing machine in- 2,713,865 Patented `luly 26, 1955 ICE Y position so that water under pressure is supplied to the cluding a generally closed framework 9 having doors 11 at its opposite sides (only the left door being shown), movable in vertical guides (not shown), and which doors when elevated permit the insertion of a dish carrying basket 13 into the machine through either the right or left side thereof.

The dishes in the basket are adapted to be washed by soapy water or similar liquid issuing from upper and lower conduits 15 connected to an electric motor driven pump 17, which pumps soapy water from a sump 19 to the conduits, the water falling into the sump after being directed onto the dishes. Thereafter, the dishes are adapted to be rinsed with fresh water issuing from nozzles 23 of upper and lower fresh water conduits 25.

Since the left and right doors are identical in construction and mode of operation, only the left door will be described in detail, and will be referred to simply as door 11. Door 11 is adapted to be hydraulically elevated by a hydraulic actuator generally entitled 27 secured to frame 9, as shown in Fig. 2. Actuator 27 includes a cylinder 29 and telescopic pistons 31 and 32, the upper piston engaging an ear 35 formed on the upper end of door 11. Lower piston 31 is tubular in formation and closed by a plug 36 at its lower end, said plug carrying a seal 37 for sealing against the interior of cylinder 29. Piston 33 can be either solid or tubular in formation, but in any event it is closed at its bottom and carries a seal 38 for sealing engagement with interior of tubular piston 3l.

Hydraulic fluid is adapted to be supplied to the hydraulic actuator 27 through a conduit 39 which is connected to a valve 41. Valve 41 is spring biased to an open hydraulic actuator from a water pressure line 43. Therefore, door 11 is normally maintained open but can be closed by turning valve 41 to a position to communicate conduit 39 with a drain conduit 45, which empties into weir 47 which in turn empties into sump 19.

A solenoid 49 is provided to enable rotation of valve 41, but its operation and connection in the control circuit of the machine will be explained hereinafter, as will the explanation of the operation of a pump motor control solenoid 51 (see Fig. 5) for controlling the operation of the pump 17.

Rinsing conduits 25 are connected by a valve 53 to the water pressure line 43, said valve being spring loaded to closed position as shown in Fig. 1 and adapted to be moved to open position at the proper time by energization of a solenoid 55.

Sump 19 is adapted to be filled before washing each load of dishes and drained thereafter by a mechanism to be presently described, but of immediate importance is the control circuit for controlling the parts described above.

Referring to Fig. 5, there is disclosed a timer motor 57 connected to the negative side 59 and to the positive side 61 of an electric current input line. Lead 61 has connected therein a manually operable switch 63, which is the main control switch of the machine, and which switch is spring biased to open position so as to assume an open position unless depressed. Timer motor 57 can be energized by depression of switch 63.

Solenoid 49 is connected across leads S9 and 61, and is therefore energized any time switch 63 is closed and functions to move valve 41 to a drain position, so that the fluid in the hydraulic actuator 27 is drained therefrom to allow the door 11 to close under the influence of gravity.

Timer motor 57 is connected to a cam 65 so that when the timer motor is energized, cam 65 is rotated to close a normally open switch 67. Switch 67 is connected by a lead 69 through a normally open microrswitch 71 to the positive side 61 of the input line. Switch 71 is mounted on the top of the machine, as shown in Fig. 1, and arranged to be closed by an ear 73 on door 11 when the door closes. It is evident therefore that switch 63 must be held closed until switch 71 is closed by door 11, or else the cycle of operation is interrupted. The rise on cam 65 holds switch 67 closed immediately after the energization of timer motor 57 so that after door 11 is closed (closing switch 71), the machine will remain .energized by the action of cam 65 until the small recess on the cam registers with switch 67 at which time a cycle of operation is completed.

Timer motor 57 also serves to rotate a wash'control cam 75, the rise of which is adapted to be brought around to close a normally open switch 77, after the lapse of sutlcient time to insure that door 11 has been closed. Switch 77, when closed, serves to indirectly en`` ergize the pump motor. lf door 11 is not closed for any reason whatsoever, timer motor 57 and therefore cam 75 stop before the rise of said cam reaches switch 77, so as to prevent the beginning of the washing part of the cycle until door 11 has closed.

Assuming that the operation is proceeding properly, switch 77 isrclosed after door 1l closes and energizes solenoid 51 which operates to close a switch 79 to supply current to the pump motor through leads 81 and S3, which are connected respectively to the positive and negative sides of the input line. Pump 17 serves to pump soapy water from sump 19 into conduits 15, which have openings formed therein to direct the soapy water onto the dishes, and the water after such contact falls into sump 19.

When the recess on cam 75 registers with switch 77, the washing part of the cycle is over and the rinsing part of the cycle is about to begin.

Timer motor 57 also rotates a third cam, a rinse control cam 85, having a rise lagging the rise on wash control cam 75, and adapted to engage and close a normally open switch 37 to energize solenoid 55. Solenoid 55 when energized turns valve 53 to supply fresh water to the rinsing conduits 25. The recess on cam 85 is arranged to register with switch @7 to open the same just before the recess of cam 65 registers with switch 67, i. e., just before the end of a cycle of operation.

When the cycle of operation is over, it is apparent that solenoid 49 will be de-energized so that valve 41 returns to a position Where water under pressure from conduit 43 is supplied to hydraulic actuator 27 to automatically open door 11. By the above structure, it is apparent that switch 63, after being depressed for a sufficient period of time to allow door 11 to close, can be released, and the cycle of operation of the machine will automatically continue, the machine turning itself off and causing door 11 to open to enable a basket of washed and rinsed dishes to be removed and a basket of unwashed dishes to be inserted in the machine.

An arrangement is provided for draining and filling sump 19 and this arrangement includes a movable standpipe 91 having a valve 93 formed on its lower end normally seating against a valve seat 95. Valve seat 95 is formed in an outlet elbow 97 which is connected to framework 9 as shown in Fig. 4 and is connected to an outlet pipe 99 extending therefrom.

Standpipe 91 has mounted on its upper end a spaced cap 100 which is designed to allow overflow water in the sump 19 to flow into and through the standpipe into the outlet elbow 97 and outlet conduit 99.

Extending centrally through standpipe 91 and threadedly connected at its lower end to elbow 97 is a tube 101. Extending through tube 101 is an actuating rod 103 slidably extending through packing 105 held against the upper end of tube 101 by a packing nut 107. Rod 103 at its upper end abuts against cap 100 and at its lower end slidably extends through the bottom of elbow 97 and rests against an arm 109 forming one part of a bell crank 111. Bell crank 111 is pivoted at 113 to a lug 115 on elbow 97. A tension spring 117 connects the outer end of arm 109 to framework 9 and therefore urges rod 103 upwardly so as to raise standpipe 91 to move the standpipe to a drain position. However, a solenoid 119 is provided for normally maintaining the standpipe in a closed position, said solenoid being connected to an arm 121 forming the other part of bell crank 111.

Referring to Fig. 5, the washing machine includes a switch 123 normally maintained in an open position by a ball float control 125 disposed in sump 19, but which switch is adapted to be close by the action of said control when the water is drained from said sump. Switch 123 is connected by a lead 127 through a manually controlled switch 129 to the positive side 61 of the input line. Switch 123 is also connected to a solenoid 131 which in turn is connected by a lead 133 to the negative side 59 of the rinput line. Connected in parallel with switch 131 is drain control solenoid 119.

Now, referring to Fig. l, solenoid 131 is adapted to control the operation of a valve 1.33 disposed in a conduit 135 connected at one end to the water pressure line 43 and extending at its other end into Weir 41. Valve 133 is spring biased to a closed position and is adapted to be moved to an open position to supply water to the Weir and therefore sump 19 upon actuation of solenoid 131.

The operation of the above described control arrangement is as follows. Assuming that the sump 19 is filled with soapy water and that a change of water is desired, switch 129, which is normally maintained in its solid line fill position, as shown in Fig. 5, is switched to its drain position, which is its dotted line position. In its dotted position, switch 129 de-energizes drain solenoid 119 so that spring 117 is operative to raise rod 103 and therefore raise standpipe 91 to open the standpipe valve and allow the soapy water to tlow out the elbow 97 and outlet conduit 99. As the soapy water drains from sump 19, the ball float control will operate to close switch 123, but since switch 129 is in a position to deenergize the lower part of the circuit nothing immediately happens. After the soapy water has completely drained from sump 19, switch 129 is moved to its solid line fill position at which time both drain solenoid 119 and fill solenoid 131 are energized. Drain solenoid 119 serves to cause the closing of the standpipe valve to close lthe sump 19, and ll solenoid 131 serves to turn valve 133 to a position to supply fresh water to the sump. After the water reaches a predetermined level, ball iioat control 125 opens switch 123 to terminate the filling operation. Ball float control 125 is arranged to allow water to ow into the sump to a level slightly below the upper end of standpipe 91.

lt is pointed out that drain solenoid 119 is connected across leads 59 and 61 of the input line ahead of switches 63 and 71, and therefore is energized regardless of the positions of said switches. In fact, the drain solenoid is energized any time the machine is plugged in. After each load of dishes has been washed (and, of course, rinsed), switch 129 is thrown to its drain position to drain the wash water from sump 19, and after draining, switch 129 is thrown to its closed position to refill the sump prior to the next washing.

By the present invention, a dishwashing machine has been provided in which a door or doors thereof are automatically controlled so as to be arranged normally in an open position. When a basket of dishes is shoved into the machine, a main control switch can be depressed to close the door. There is a control system incorporated in the machine so that the washing and rinsing portions of the operating cycle will not begin until the door has completely closed to close a microswitch controlling the control system. After the door is closed the main switch can be released and the machine will automatically run through its washing and rinsing operations and then automatically open the door to permit the withdrawal of the washed dishes. A drain and iill arrangement has been incorporated in the machine, to permit the draining of soapy water from the machine and the filling of the sump with fresh water by merely throwing a switch from one position to another position.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A dishwashing machine having an electrically driven timing means and a door providing access to a dishwashing chamber, a hydraulic actuator connected to said door for opening the same, conduit means for connecting said hydraulic actuator to a source of iiuid under pressure, and a solenoid controlled valve in said conduit means, said solenoid being connected in parallel with said electrically driven timing means, said valve being spring biased to an open position, whereby said hydraulic actuator is supplied with fluid under pressure to automatically open said door whenever said solenoid and said electrically driven timing means are deenergized.

2. A dishwashing machine having an electrically driven timing means and a door providing access to a dishwashing chamber, a hydraulic actuator connected to said door for opening the same, conduit means for connecting said hydraulic actuator to a source of uid under pressure, and a solenoid controlled valve in said conduit means, said solenoid being connected in parallel with said electrically driven timing means, said valve being spring biased to an open position, whereby said hydraulic actuator is supplied with fluid under pressure to automatically open said door whenever said solenoid and said electrically driven timing means are deenergized, means including a manually controlled switch for closing the circuit to said solenoid valve to permit closing of the door, said switch being spring biased toward its open position.

3. A dishwashing machine having an electrically driven timing means and a door providing access to a dishwashing chamber, a hydraulic actuator connected to said door for opening the same, conduit means for connecting said hydraulic actuator to a source of Huid under pressure, and a solenoid controlled valve in said conduit means, said solenoid being connected in parallel with said electricall` driven timing means, said valve being spring biased to an open position, whereby said hydraulic actuator is supplied with uid under pressure to automatically open said door whenever said solenoid and said electrically driven timing means are deenergized, means including a manually controlled switch for closing the circuit to said solenoid valve to permit closing of the door, said switch being spring biased downward its open position, separate circuit means for independently supplying current to said solenoid Valve and to said electrically driven timing means irrespective of the position of said manually controlled switch, said separate circuit means including a switch adapted to be closed by said door when said door reaches its fully closed position.

References Cited in the le of this patent UNITED STATES PATENTS 2,002,300 Stoddard May 21, 1935 2,154,559 Bilde Apr. 18, 1939 2,358,507 Haberstump Sept. 19, 1944 2,425,620 Kempton Aug. 12, 1947 2,647,528 Barngesser et al Aug. 4, 1953 

